A practical access to highly enantiomerically pure flavanones by catalytic asymmetric transfer hydrogenation.

A surprisingly selective, non-enzymatic kinetic resolution of readily available, racemic ß-chiral ketones enabled the title process, which was applied to a rapid synthesis of several bioactive flavanones in virtually enantiopure form (see scheme; MOM=methoxymethyl, Ts=p-toluenesulfonyl).